The present inventive concept relates to a multilayer ceramic capacitor and a board having the same.
Capacitors, inductors, piezoelectric elements, varistors, thermistors, and the like, are representative electronic components using a ceramic material.
Among such ceramic electronic components, a multilayer ceramic capacitor (MLCC) is commonly used in a wide range of electronic apparatuses due to inherent advantages thereof, such as a relatively small size, relatively high capacitance, and an ease in the mounting thereof.
For example, such a multilayer ceramic capacitor may be used as a chip-type condenser mounted on the boards of various electronic products such as image display devices, including liquid crystal displays (LCDs), plasma display panels (PDPs), and the like, as well as computers, personal digital assistants (PDA), and mobile phones, serving to charge electricity therein or discharge electricity therefrom.
Such a multilayer ceramic capacitor may have a structure in which a plurality of dielectric layers and internal electrodes having opposing polarities are alternatingly disposed with respective dielectric layers alternatingly interposed therebetween.
In this case, since the dielectric layer has piezoelectric characteristics, when a direct current (DC) voltage or an alternating current (AC) voltage is applied to such a multilayer ceramic capacitor, a piezoelectric phenomenon may be generated between the internal electrodes, thereby generating periodic vibrations, while expanding and contracting a volume of a ceramic body according to the frequency of the voltage applied thereto.
These vibrations may be transferred to the board through external electrodes of the multilayer ceramic capacitor and solders connecting the external electrodes and the board to each other, such that the entire board is used as a sound reflecting surface generating vibrational sound, commonly known as noise.
Such vibrational sound may correspond to noise within an audio frequency range of 20 to 20,000 hertz (Hz), sound which may cause discomfort to listeners thereof. Vibrational sound causing listener discomfort, as described above, may be termed acoustic noise.